Abbreviation of difference.
"Before we start coding, let's look at the diff between my branch and the main repository to see what changes were made."
In plain English: A diff is a side-by-side view that shows exactly what changed between two versions of a file.
"The diff showed exactly which lines were changed in my code."
Usage: Diff is not standard English and should be avoided in formal writing; use the word "difference" instead. It is only appropriate as an informal abbreviation in casual text messages or code comments where space is limited.
To run a diff program on (files or items) so as to produce a description of the differences between them, as for a patch file.
"Before submitting the code update, I need to diff my local branch against the main repository to see exactly what lines changed."
In plain English: To diff something means to make it less intense or spread out so it doesn't seem as bad.
"I need to diff my resume before I send it to potential employers."
Usage: Do not use "diff" as a verb in everyday conversation; it is strictly technical jargon for comparing files using software. In regular speech, people say "compare," "contrast," or "check the differences" instead.
A program, historically part of the Unix operating system, which compares two files or sets of files and outputs a description of the differences between them.
"The developer ran diff on the version control logs to quickly identify exactly which lines changed after yesterday's update."
Derived from the Latin verb diffringere, meaning "to break in pieces," this term originally referred to breaking something apart before evolving into an abbreviation for "differentiate" or "differ." It is now commonly used as a short form of "difference" in computing and general speech.